Full drive encryption with Bitlocker freezes at 99.9%

I have enabled Bitlocker for fully encrypting a partition/drive on my disk a few days ago (it took some hours to reach 99.9% completion). This partition only contains a few GB of data (which Windows 10 programs do not need to access).

Ever since, after I shutdown/restart the computer and unlock that drive, the progress bar window shows up again and always stops at 99.9%. Bitlocker lock mechanism seems to be working properly, i.e. I cannot access the drive without the password and only when I unlock it, the progress bar shows up again.

Is this a normal behavior? What are the remaining 0.1% that are left to encrypt? Can I fix this without deactivating Bitlocker?

4 Answers

I purchased a refurbished PC for the office that came with a 446GB SSD as the primary disk. I faced the same situation as the OP...the encryption stage would always get to 99.9% completion and go no further. chkdsk turned up no disk errors. Resetting the TPM didn't help. Telling BitLocker to use the older encryption algorithm versus the newer didn't help. Encrypting only the used space versus the entire disk made no difference either.

What finally worked was to use the Disk Management tool to shrink the primary partition by some random number of Gigabytes (I chose to shrink off 40GB). I then enabled BitLocker again and this time it ran until the disk was 100% encrypted and it completed successfully. I was then able to go back into the Disk Management tool and enlarge the primary partition to reclaim the 40GB of space I had shrunk off earlier. In the end I had access to the full amount of original disk space and BitLocker was fully enabled.

1. To bring up the Disk Management tool, press Win+R then enter diskmgmt.msc:

2. Right-click on the drive you are trying to enable BitLocker on (in my case it was "C:") and choose "Shrink Volume...":

3. Tell it how much you want to shrink the volume by (screen not shown here). When finished, the shrunk space will appear as unallocated space to the right of the drive:

4. Now return to the BitLocker management window and enable BitLocker again. For me, the encryption now ran to 100% and successfully completed:

5. You can now return to the Disk Management tool and reclaim the shrunk space. To do this, right-click on the drive you previously shrunk and select "Extend Volume...":

6. Tell it to reclaim all the unallocated space (screen not shown here). When finished, the drive should be back to its original full size, and the entire drive should still be BitLocker protected:

If you have another Windows 10 computer, plug the disk into that computer (pausing the encryption beforehand) and see if the encryption process completes. If it doesn't after a few hours, assume the encryption is borked. Remove the BitLocker Encryption (if possible) then re-encrypt it on the other system.

If not, then you can either

Clear your TPM

1. Remove the BitLocker Encryption

2. In your BIOS/UEFI settings, clear/reset the TPM.

3. Reboot your computer.

4. Re-encrypt your drive.

5. If it's still stuck at 99.9%, try the below.

It is paramount you follow these instructions word-by-word; if you reset the TPM before BitLocker is disabled, You will lose ALL your data!

Reinstall Windows

or

Assume that your disk has failed in some way.

It seemed to me like pausing and unpausing it seemed to give the encryption process a kick once it got stuck.

I have a new 1.5 TB Western Digital external hard disk, where I need to Bitlocker encrypt it for first use. It soon went till 99.9% and stuck there.

After Pause, Resume, Pause, Resume three times the pop up closed. Then removing the disk and reinserting it solved the issue. Make sure you don't remove the disk when pop-up for encryption is still open. Let it close, by doing Pause, Resume continuously.